The present invention relates to an adjustable presser foot device for straight bar knitting machines with double V-shaped needle beds which permits the machine to knit rib border and jersey without the need for any particular manual interference or interruption of machine operation.
Passing from one mode of knitting to another in the prior art was limited to machines equipped with a conventional reed or roller traction device. With a presser foot type of machine, however, it was necessary, in order to fabricate composite panels or pieces, either to knit the jersey part and to later attach thereto one of several separately knitted rib top borders, or to knit false rib borders with elastic thread, of the type produced on single cylinder circular knitting machines.
A knitting machine employing a conventional presser foot device without means for enabling the presser foot to automatically function along two separate levels is disclosed in U.S. Pat. No. 3,613,401 issued to JEFFCOAT et al on Oct. 19, 1971. The optimum operating levels of presser feet when rib and jersey are being knit are described fully in the specification of that patent, and the general layout of a knitting machine using presser feet of the general type disclosed herein is fully described.
The present invention has application in such an environment, and the present drawings and specification describe only those details necessary for a person skilled in the relevant art to understand and practice the invention.
Reference is also made to U.S. Pat. No. 3,842,623 issued to FLAVELL et al on Oct. 22, 1974 for additional description of the state of the art of knitting machines using presser foot elements.